It is known to provide mobile self-propelled crushing and screening machines for processing materials, such as aggregates, in a quarry or for recycling demolition waste.
Such machines typically comprise a chassis having one or more material processing devices mounted thereon for screening, separating, crushing and/or washing one or more types of aggregate material, for example rocks, stones, gravel, sand and/or soil, or any other material that is quarried, mined or excavated.
Typically, the processing machine is mobile and comprises one or more wheels and/or tracks mounted on the chassis. The machine is usually self-propelled incorporating a drive unit, such as an engine, for driving the wheels and/or tracks.
Typically a feed hopper is provided for receiving material to be processed, the hopper being mounted above a loading end of a feed conveyor, the feed conveyor having a discharge end for delivering the material to the one or more material processing devices.
It is desirable to locate the feed hopper at a relatively low level to reduce the need to raise material to be loaded into the feed hopper onto the feed conveyor. The discharge end of the feed conveyor is required to be located at a higher level so that the material can be fed under the action of gravity to said one or more processing devices, such as a crushing device or screening device. Therefore the feed conveyor is typically upwardly inclined. However, if the angle of inclination of the feed conveyor is too steep, the feed conveyor may be unable to deliver heavier material to the one or more processing devices as the material may simply roll down the conveyor. Therefore it is desirable to permit adjustment of the angle of inclination of the feed conveyor to suit the material being processed.